Be very careful. Ellie Goulding is a potentially fatal drug, and her most powerful side effect is halcyon. Released this past October, “Halcyon” is her highly anticipated second album. Known for a hypnotic synth sound, she has established herself as a versatile, ­innovative pop artist.

When she burst onto the music scene with “Lights” in 2010, the British singer made it brilliantly clear that she is not your run-of-the-mill pop star. “Lights,” the single from her debut album, controlled airwaves and scaled the charts internationally, introducing the world to her electro-dance pop beats and evocative vocals.

In the music world, a successful second album is one of the most difficult feats. Not disappointing for a second, “Halcyon” pushes the boundaries of the indie dream pop genre. Goulding recorded in solitude in her hometown of Hay Valley, West England, calling upon inspirations such as the ocean, countryside, and human body. “Halcyon” shows off her maturity as an artist and as a person.

The first single, “Hanging On,” is a hauntingly beautiful cover of the obscure Active Child original. While both are fantastic, her clever additions of dub-step pulses and layered robotic harmonies add freshness. Other standouts are “My Blood” and “I Know You Care.” The first is a poignant song summarizing the inspiration for her album. The listener gets a sense of what she stands for and what she wants to accomplish as an artist – she exposes herself for the sake of her art in a way that few artists successfully accomplish. “I Know You Care” is probably the biggest change for her; with no synthesizers, or driving drum beats – only her vocals and a piano. The fantastic thing about Goulding's musical ability is that regardless of whether she chooses a ballad, an acoustic cover, or a dub-step dance track, her audience is never bored.

Goulding has set herself up for success. “Halcyon” has something for many types of listeners. Those looking for a post-breakup song will drift toward slower songs like “Dead in the Water” or “Explosions.” Listeners who favor a fist-pumping, head-bopping dance track might like “I Need Your Love” and “Without Your Love.” People searching for a dramatic, teen-angsty song, will find “Don't Say a Word” or the title track to their liking. There are tracks that seem to be simply filling space, such as “Atlantis” and “Joy.” However, Goulding cleverly makes up for these with the final four on the deluxe edition, where she toys with tribal beats and Skrillex-esque background music to accompany her.

There's only one thing left to ask: what will Goulding do now? That is her strength – she always keeps fans guessing.